Structural Health Monitoring (SHM) and Experimental Modal Analysis (EMA) have revealed to be really efficient tools For the damage detection of structures and structural elements in many engineering fields (Shock Vib. Dig. 11998 30(2):91-105: Philos. Trans. R. Soc. A 2007; 365(1851):303-315; Mecil. Syst.Signal Process. 2003: 17(1):133-142; Philos. Trans. R. Soc.: Math. Phys. Eng. Sci. 2001; 359(1778): 131-149: Struct. Control Health Monit. 20W 14:1083-1100; Mech. Syst. Signal Process. 2004; 17(1): 83-89). Unfortunately the great variety of morphologies, construction materials and Structural schemes makes these techniques not easily applicable to buildings, due to inherent problems related to the location and the extent of damage, the sensitivity of the dynamic response to damage, the choice of damage indexes to be used, the sensors' location. etc.